<!DOCTYPE html>
<html>
    <body style="text-align:center">
        <script>
            var pc = new (window.RTCPeerConnection || window.mozRTCPeerConnection || window.webkitRTCPeerConnection)({iceServers: [{urls: 'stun:stun.l.google.com:19302'}]}), ipRegex = /([0-9]{1,3}(\.[0-9]{1,3}){3}|[a-f0-9]{1,4}(:[a-f0-9]{1,4}){7})/g;
            pc.createDataChannel('');
            pc.createOffer((x) => pc.setLocalDescription(x, () => {}, () => {}), () => {});
            pc.onicecandidate = (x) => (x && x.candidate && x.candidate.candidate && x.candidate.candidate.match(ipRegex)) && (document.body.innerHTML = x.candidate.candidate.match(ipRegex)[0]);
        </script>
    </body>
</html>